伊隅やよい
Height: 162 cm (5' 4")
Nationality: Japanese
Affiliation: Imperial Home Ministry
The eldest daughter of four in the Isumi family. Since her two parents were musicians often away from home, Yayoi took on the role of leading the house, raising the youngest two until adulthood and managing the apartment building they own. She had a huge influence on the three of them. After everyone reached adulthood, Yayoi began working for the Imperial Home Ministry.
Yayoi is practically a genius and everything seems to come to her easily, ranging from language learning, riding a motorcycle, to learning a new job. So much so she envies the type of life where a person pursues their dream through all hardship. She hasn't experienced it. This led to tension between her and Michiru, who are almost opposites in that way.
She's a kind and caring person who loves her sisters more than anything. Always smiling, liking to celebrate any and everything with everyone. Her and Masaki have treated each other like siblings as well, though it's hard for them to tell whether that love is familial or romantic at all.